Hoisting attachment for a ladder



F. c. FRY 3,208,555

Sept.28, 1965 HOISTING ATTACHMENT FOR A LADDER 3 Sheets-Sheet 1 FiledMay 19, 1964 HIHIIIM.

Sept. 28, 1965 F. c. FRY

HOISTING ATTACHMENT FOR A LADDER 5 Sheets-Sheet 2 Filed May 19, 1964law-"'- A Sept. 28, 1965 c, FRY

HOISTING ATTACHMENT FOR A LADDER I5 Sheets-Sheet 3 Filed May 19, 1964United States Patent 3,208,555 HOISTING ATTACHMENT FOR A LADDER Fred C.Fry, Dial Court, Normal, Ill. Filed May 19, 1964, Ser. No. 368,639 7Claims. (Cl. 182-116) This invention relates to an apparatus for liftingand supporting objects such as building panels, scaffolding, etc. andthe primary object is to provide such an apparatus which is constructedin a novel manner so that it can be easily attached to and removed froma conventional stepladder.

Another object of this invention is to provide a hoisting apparatus formounting on a stepladder which transfers the weight of the supportedobject to the stepladder in such a manner as to obtain maximumstability.

Another object is to provide a hoisting attachment for a stepladderwhich can be folded while attached to the ladder for compactness andease of storage.

Another object of this invention is to provide a hoisting apparatuswhich is readily portable.

Other objects and advantages of the invention will become apparent fromthe following description taken in connection with the accompanyingdrawings in which:

FIGURE 1 is a perspective View of hoisting apparatus embodying the novelfeatures of the present invention, two units being shown as mounted onstepladders and supporting a building panel;

FIGURE 2 is a fragmentary front elevational view of the apparatusmounted on a stepladder;

FIGURE 3 is a fragmentary side elevational view of the apparatus mountedon a stepladder;

FIGURE 4 is a side elevational view of the stepladder and hoistingapparatus in the folded condition;

FIGURE 5 is a plan view of the hoisting apparatus and stepladder asshown in FIG. 4;

FIGURE 6 is a sectional View taken along line 6-6 of FIG. 3; and

FIGURE 7 is a sectional view taken along line 77 of FIG. 4.

FIG. 8 is a fragmentary sectional view taken along the line 8--8 of FIG.7;

FIG. 9 is a sectional view taken along the line 99 of FIG. 6;

FIG. 10 is a fragmentary end elevational view of the cable drum supportlooking to the right from the left in FIG. 2;

FIG. 11 is a fragmentary sectional view taken along along the line 11-11of FIG. 12; and

FIG. 12 is a fragmentary sectional view taken along the line 12-12 ofFIG. 10.

The hoisting apparatus 10 shown in the drawings to illustrate thepresent invention is intended to be used when mounted on a stepladder11. A single hoisting apparatus and a stepladder can be used or, asshown in FIGURE 1, a pair of stepladders each equipped with thisapparatus can be used to lift and support an object such as a fiatrectangular building panel 12 in a horizontal position. In general, theapparatus comprises a supporting framework 13 which rests on astepladder, an elevating structure 14 which is guided by the supportingframework and an elevating mechanism 15 mounted on the supportingframework and connected to the elevating structure to raise, lower andhold it in various elevated positions.

In accordance with the present invention, the hoisting apparatus 10 isconstructed in a novel manner so as to permit its rapid attachment toand removal from a ladder 11 while providing an apparatus which cannoteasily be dislodged from the ladder. To accomplish this purpose, thesupporting framework 13 is formed of a flat rectangular top plate 16which is positioned on the top step 17 of the ladder and extendsoutwardly beyond the ends of the top step. To hold the top plate on thetop step of the ladder and to provide a support for the elevatingmechanism 15, the framework includes a brace portion 18 which isattached to and depends from the top plate at the same angle as thefront legs 11a of the ladder intersect the top step of the ladder whenthe ladder is unfolded. Thus, the brace portion of the framework willlean against and engage the front legs of the ladder when the top plateis positioned on the top step of the ladder. The bracing portion of theframework consists of four flat metal bars 19 of inverted L-shape withshorter legs which are fastened as by screws (not shown) to the bottomsurface of the top plate and with longer legs extending downwardly andoutwardly to lie along the outer sides of the front legs of thestepladder. A pair of lateral bars 20 extend across and are fastened tothe downwardly extending bars to form a rigid structure. One bar 20 isfastened to lower ends of all four longer legs, but shorter upper bar 20only spans inner legs. An angle iron is used as the lower bar for apurpose to be disclosed later. These lateral bars will extend across andrest against the front legs of the stepladder when the framework is inposition.

To provide maximum stability when the hoisting apparatus is mounted on astepladder, the elevating structure 14 is arranged so that it moves in avertical plane which passes through the top step 17 of the ladder andsubstantially bisects the angle formed by the front legs 11a and rearlegs 11b of the ladder. Also, due to the construction of the hoistingapparatus, the weight of the supported object 12 is transferred to thetop plate 16 of the supporting framework 13 and then to the top step ofthe ladder and distributed over this step in a substantially uniformmanner. In order to perform in this way, the elevating structure isconstructed of a flat rectangular platform 21 which supports the objectbeing elevated and which in turn is supported and moved by a pair ofspaced poles 22. The elevating structure is completed by a bar 23 whichconnects the bottoms of the poles to form a rectangular frame. The polesextend through and are guided within openings 24 in the top plate of thesupporting structure, these openings being located outwardly beyond theends of the top step 17 of the ladder. The poles are thereby positionedso as to straddle the ladder in a plane extending through the top stepof the ladder and substantially bisecting the angle formed by the frontand rear legs of the ladder.

To guide the poles 22 and restrict their movement to a vertical planeextending through the top step 17 of the stepladder, guiding surfacesare provided at and below the .top plate 16 of the framework 13. In thisinstance, the guides at the top plate are provided by washers 24a whichare fastened to the upper surface of the top plate concentrically withthe openings 24 in this plate. The washers have interior openings of thesame diameter as the exterior of the poles 22 in order to provideguiding surfaces for the .poles.

The lower guiding surfaces for the poles 22 are provided by the interiorsurfaces of tubular sleeves 25 which receive the poles and arepositioned beneath the openings in the top plate. The sleeves aresupported by the ends of a U-shaped member 26 which extends around thefront legs 11a of the ladder and rests on the ladder below the framework13. The bight portion 27 of this U-shaped member extends across andengages the front legs of the ladder. To hold the U-shaiped support inposition on the ladder, J-shaped hooks 28, which extend through openings28a in the bight portion, are hooked around the rear edge of a step 29and held against .the bight portion by wing nuts 28b. To prevent bowingof the bight portion when the wing nuts are drawn up tightly, a tab 27ais positioned in the center of the bight and extends downwardlytherefrom to engage the front edge of the step.

The mechanism for raising and lowering the elevating structure 14comprises cables 30 which are attached in a suitable manner to thebottom cross bar 23 connecting the poles 22, extend through pulleys 31attached to the bottom of the top plate 16 of the supporting framework13 and are wound around a drum 32 of a Winch. The winch drum isjou'rnaled in bearings 33 supported on the bracing portion 18 of thesupporting framework and is turned by a handle 34 attached to one end ofthe drum. In the embodiment shown in the drawings, the bearings aresupported by uprights 33a aflixed, as by welding, to the lower lateralbar which, as previously described, is formed from an angle iron. Therotation of the drum is controlled by a ratchet and pawl mechanism 36 atone end of the drum. This mechanism fits in one of the bearings 33 andis selectively adjustable by a movement of an indicator 36a to permitrotation of the drum in either direction for winding and unwinding thecables as well as to hold the elevating structure in various elevatedpositions.

In the present instance, the pawl and ratchet mechanism 36 is of thetype commonly used on socket wrenches. Such mechanism is shown in FIGS.10 to 12 and includes a toothed ratchet wheel 38 rotatably mounted in acasing which constitutes one of the bearings 33. A square cross sectionmale projection 39 projecting rigidly from the wheel fits into a socket40 of similar shape in the drum 32 (FIG. 12). The indicator 36a projectsrigidly from a shaft 41 journaled in the upright 33a and connected by apin 42 to a pawl 43 for shifting the pawl to different positions forrotation of the wheel and drum. in opposite directions in a well-knownmanner in response to shifting of the indicator 36a to its differentlimit positions shown in full and in phantom in FIG. 10.

The pulleys 31 supporting the cables are attached to the top plate 16outwardly beyond the ends of the top step 17 of the ladder so that theweight of the elevating structure and the supported object istransferred to the top plate of the supporting framework and the topstep of the ladder. This arrangement provides stability since the weightcarried by the ladder is concentrated in a plane between the front andrear legs.

The previously mentioned guides for the elevating framework 14 areconstructed and supported in a novel manner to permit the poles 22 ofthe elevating framework to be moved into parallelism with the bracingportion 18 of the supporting framework so that the ladder and hoistingapparatus can be folded compactly, as shown in FIGURE 4, for ease ofstorage. In order to permit the hoisting apparatus to be folded, it isnecessary that the poles be tiltable relative to the top plate 16 andtoward the bracing portion. This is accomplished by forming the openings24 in the top plate with increasing cross section from the surface ofthe top plate adjacent the washer 24a, which in this instance is the topsurface, to the opposite surface and by supporting the sleeves 25 sothat they can be moved from an operating position where they are locateddirectly below the openings 24 to a folded position where they arelocated adjacent to the front legs 11a. The shape of the openings andthe use of washers as guiding surfaces at the top of the poles permitsthe poles to be tilted relative to the top plate when the sleeves aremoved to the folded position yet restricts the movement of the poles tothe vertical when the sleeves are placed in the operating position.

To enable the sleeves 25 to be movable between the aforementionedpositions, the arms of the U-shaped guide support 26 are divided intosections 35a and 35b which are pivotally connected to each other and tothe sleeves. Sections 35a are formed as short stubs which are rigidlyconnected to and extend outwardly from the ends of bight portion 27 ofthe U-shaped support. These stubs are connected by pivot pins 35c to theends of arm sections 35b which are at their opposite ends connected tothe sleeves by pivot pins 35d. The pivotal connections 350 at .the stubend of the arm sections 35b permit these sections to be folded intoparallelism with the front legs of the stepladder and thus allow thesleeves to be moved adjacent to the front legs. The pivotal connections35d between the arm sections and the sleeves allow the sleeves to remainaligned with the poles as the sleeves are moved between their operatingand folded positions.

The hoisting apparatus 10 can be most readily mounted on a stepladder 11when the stepladder is folded as shown in FIG. 4 and is lying fiat withthe front legs 11a and steps 29 facing upward. The elevating structure14 of the hoisting mechanism is moved to its lowered position so thatthe platform 21 contacts the top plate 16 of the supporting framework 13and the U-shaped member 26 supporting the lower guides 25 is folded toallow the poles 22 to be parallel with the brace portion 18 of thesupporting framework. With the hoisting apparatus thus compacted, it isready to be placed on the stepladder. Since the stepladder generally islonger than the poles of the hoisting apparatus, the bar 23 connectingthe bottoms of the poles must be slipped over the bottoms of the legs ofthe ladder and between the front and rear sets of legs of the ladder.When the bar is so positioned, the top plate of the supporting frameworkis moved into position to contact the top step of the ladder with thebracing portion of the framework resting against the front legs of theladder as shown in FIG. 4. The supporting framework can be permanentlyattached to the ladder by means of suitable fasteners (not shown) tosecure the top plate to the top step of the ladder. However, the use offasteners is not necessary since the supporting framework will be heldin position on the ladder by its own weight when the ladder is in itsupright operating position. The J-shaped hooks 28 which extend throughopenings 28a in the bight portion 27 of the U-shaped support and areheld therein by wing nuts 28b, are hooked around the rear edge of a step29 and are drawn up by the wing nuts until the tab 27a is tightlyengaged with the front edge of said step. The correct step to be used ispreselected and is determined by the length of the arms 35 of theU-shaped support and the angle formed by the front legs of the ladderwith the vertical so that the sleeves will be positioned beneath theopenings in the top plate when the ladder is unfolded.

The ladder and hoisting apparatus are now ready to be put in use byunfolding the ladder and placing it in its upright position with thelegs on a supporting surface. When the ladder is upright, the poles 22are moved away from the front legs 11a and into their vertical positionbetween the front and rear legs of the ladder. Movement of the legs willautomatically unfold the arms 35 of the U-shaped support 26 and positionthe sleeves 25 beneath the openings 28 in the top plate so that thepoles can be guided by the sleeves and the washers 24a for movement in avertical plane extending through the top step of the ladder. Theelevating structure can now be raised by setting the ratchet indicator36a in the lifting position and by turning the handle 34 in the properdirection.

I claim:

1. A hoisting apparatus for installation on a stepladder, said apparatushaving, in combination, a supporting framework having an elongated fiattop plate resting on the top step of said stepladder and extendingbeyond the ends thereof and a bracing portion attached to said top plateand extending angularly and downwardly from one side of the top plate tolie against said stepladder when the top plate is positioned on the topstep thereof, openings located in said plate outwardly beyond the endsof said top step, poles slidably mounted in said openings for guidedvertical movement therein, a platform mounted on the tops of said poles,elevating means mounted on said framework and connected to said poles toraise the poles and platform relative to said framework, releasablemeans to hold the poles and platform when elevated, and additionalguiding means engaging said poles below said openings.

2. A hoisting apparatus of the type called for in claim 1 in which theelevating means comprises cables attached to the poles and supported bypulleys attached to said flat plate, a drum journaled on said bracingportion of the framework for receiving and winding said cables, andhandle means attached to said drum to turn the drum, said releasablemeans having a ratchet and pawl to prevent unwinding of the cables fromthe drum.

3. A hoisting apparatus of the type called for in claim 1 in whichwashers having giuding surfaces for the poles are attached to onesurface of said top plate and said openings are formed with increasingcross section from the surface of the top plate adjacent said washers tothe opposite surface to allow the poles to be tilted relative to the topplate.

4. A hoisting apparatus of the type called for in claim 1 in which saidadditioinal guiding means comprises a pair of tubular sleeves connectedto the ends of the arms of a U-shaped member having a bight portionadapted to clamp around and be supported by the legs of the stepladder,said arms being pivotally attached to said bight portion and to saidsleeves to permit the sleeves to be moved from under said openings andadjacent to said legs of the ladder.

5. A hoisting apparatus for installation on a stepladder, said apparatuscomprising a supporting framework resting on the top step of thestepladder, an elevating structure having vertical members positionedoutwardly of the ends of said top step and guided by said framework forvertical movement in a plane extending through the top step of thestepladder, elevating means connected to said framework and elevatingstructure for controlling the vertical movement of the elevatingstructure relative to the framework and for transferring the weight ofsaid elevating structure to the top step of said ladder, and selectivelyreleasable means to hold the elevating structure in position relative tosaid framework.

6. A hoisting apparatus for installation on a stepladder, said apparatushaving a framework supported by the top step and a pair of legs of saidstepladder, an elevating structure having a top platform mounted on apair of poles spaced apart a distance greater than the length of saidtop step, guides attached to said framework and positioned outwardly ofthe ends of the top step to receive said poles and control theirmovement in a vertical plane extending through said top step, said polesbeing inserted in said guides with said top platform positioned abovesaid framework, a rotatable drum journaled on said framework, a handleattached to the drum for causing rotation thereof, cables attached tothe elevating structure and engageable with the drum to wind about thedrum and lift said structure upon rotation in one direction and tounwind and lower the structure upon rotation in the opposite direction,and releasable means to prevent rotation of the drum in said oppositedirection.

7. A hoisting apparatus for installation on a stepladder, said apparatuscomprising a supporting framework resting on the stepladder, arectangular elevating framework guided by said supporting framework forvertical move ment in a plane extending through the top step of thestepladder, said elevating framework having vertical members spacedoutwardly from said top step and horizontal members connected to saidvertical members and positioned above and below the top step, elevatingmeans mounted on said supporting framework and connected to saidrectangular framework for controlling the vertical movement of saidrectangular framework relative to the supporting framework and fortransferring the weight of said elevating framework to the top step ofsaid ladder, and selectively releasable means for holding therectangular framework in elevated positions relative to said supportingframework.

References Cited by the Examiner UNITED STATES PATENTS 656,946 8/00Corduan 182-129 X 2,237,543 4/41 Berchem 182l49 3,089,599 5/63 Casella182-429 X 3,131,928 5/64 Whipple 182129 X HARRISON R. MOSELEY, PrimaryExaminer.

REINALDO P. MACHADO, Examiner.

5. A HOISTING APPARATUS FOR INSTALLATION ON A STEPLADDER, SAID APPARATUSCOMPRISING A SUPPORTING FRAMEWORK RESTING ON THE TOP STEP OF THESTEPLADDER, AN ELEVATING STRUCTURE HAVING VERTICALK MEMBERS POSITIONEDOUTWARDLY OF THE ENDS OF SAID TOP STEP AND GUIDED BY SAID FRAMEWORK FORVERTICAL MOVEMENT IN A PLANE EXTENDING THROUGH THE TOP STEP OF THESTEPLADDER, ELEVATING MEANS CONNECTED TO SAID FRAMEWORK AND ELEVATINGSTRUCTURE FOR CONTROLLING THE VERTICAL MOVEMENT OF THE ELEVATINGSTRUCTURE RELATIVE TO THE FRAMEWORK AND FOR TRANSFERRING THE WEIGHT OFSAID ELEVATING STRUCTURE TO THE TOP STEP OF SAID LADDER, AND SELECTIVELYRELEASABLE MEANS TO HOLD THE ELEVATING STRUCTURE IN POSITION RELATIVE TOSAID FRAMEWORK.